.wrapper {
  width: 30%;
  display: inline-block;
  padding-bottom: 1em;
}

.wrapper h1 {
  text-align: center;
  font-size: 1.5em;
}

.cube {
  font-size: 2em;
  width: 2em;
  height: 2em;
  margin: .5em auto;
  transform-style: preserve-3d;
  perspective: 250px;
}

.w1 .cube {
  perspective-origin: top left;
}

.w2 .cube {
  perspective-origin: top;
}

.w3 .cube {
  perspective-origin: top right;
}

.w4 .cube {
  perspective-origin: left;
}

.w5 .cube {
  perspective-origin: center;
}

.w6 .cube {
  perspective-origin: right;
}

.w7 .cube {
  perspective-origin: bottom left;
}

.w8 .cube {
  perspective-origin: bottom;
}

.w9 .cube {
  perspective-origin: bottom right;
}

.side {
  position: absolute;
  width: 2em;
  height: 2em;
  background: rgba(255, 99, 71, 0.6);
  border: 1px solid rgba(0, 0, 0, 0.5);
  color: white;
  text-align: center;
  line-height: 2em;
}

.front {
  transform: translateZ(1em);
}

.top {
  transform: rotateX(90deg) translateZ(1em);
}

.right {
  transform: rotateY(90deg) translateZ(1em);
}

.left {
  transform: rotateY(-90deg) translateZ(1em);
}

.bottom {
  transform: rotateX(-90deg) translateZ(1em);
}

.back {
  transform: rotateY(-180deg) translateZ(1em);
}
